小编Nic*_*tka的帖子

我正在尝试编写一个文件上传脚本以在安全的企业内部网中使用，但遇到了一些麻烦......

在下面的代码中，我没有收到任何错误，我所有的调试看起来都在工作，但最终结果总是一个“空白”图像：

var ctx = document.createElement('canvas');
var img = new Image();
img.onload = function(){
    ctx.drawImage(img,0,0);
}
img.src = $('#UpdateImage:file');

var imgStr = ctx.toDataURL("image/png", "");
document.getElementById("Item_Create_Image_Avatar").src = imgStr;

当我在 'Item_Create_Image_Avatar' 对象上“检查元素”时，'src' 值看起来非常完美：

<img src="data:image/png;base64,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" id="Item_Create_Image_Avatar" style="vertical-align:top">

为什么我的图像是空白的？

我认为这会相当容易但我在这里......我只是想在现有的地方添加一个新行, DataTable但是这个表不会占用我的行......

Debug.Print("My Achv Count Before: {0}", Manager.achievementsMine.Rows.Count);
DataRow newRow = Manager.achievementsMine.NewRow();
newRow.SetField<int>("CT_Q", count);
newRow.SetField<DateTime>("CMPL_D", DateTime.Now);
newRow.SetField<string>("USER_LAN_I", Manager.userID);
newRow.SetField<string>("ACHV_I", ACHV_I);
Manager.achievementsMine.ImportRow(newRow);
Manager.achievementsMine.AcceptChanges();
Debug.Print("My Achv Count After: {0}", Manager.achievementsMine.Rows.Count);

'Debug.Print'之前/之后的行都显示为44.为什么'after'调试告诉我45因为我刚刚导入一个新行并告诉DataTable接受更改？

编辑:我尝试重写一些newRow部分,但没有改变:

Debug.Print("My Achv Count Before: {0}", Manager.achievementsMine.Rows.Count);
DataRow newRow = Manager.achievementsMine.NewRow();
newRow["CT_Q"] = count;
newRow["CMPL_D"] = DateTime.Now;
newRow["USER_LAN_I"] = Manager.userID;
newRow["ACHV_I"] = ACHV_I;
Manager.achievementsMine.ImportRow(newRow);
Manager.achievementsMine.AcceptChanges();
Debug.Print("My Achv Count After: {0}", Manager.achievementsMine.Rows.Count);